Add fmod_ret BPF program to existing test_overhead selftest. Also re-implement
user-space benchmarking part into benchmark runner to compare results. Results
with ./bench are consistently somewhat lower than test_overhead's, but relative
performance of various types of BPF programs stay consisten (e.g., kretprobe is
noticeably slower). This slowdown seems to be coming from the fact that
test_overhead is single-threaded, while benchmark always spins off at least
one thread for producer. This has been confirmed by hacking multi-threaded
test_overhead variant and also single-threaded bench variant. Resutls are
below. run_bench_rename.sh script from benchs/ subdirectory was used to
produce results for ./bench.
Single-threaded implementations
===============================
/* bench: single-threaded, atomics */
base : 4.622 ± 0.049M/s
kprobe : 3.673 ± 0.052M/s
kretprobe : 2.625 ± 0.052M/s
rawtp : 4.369 ± 0.089M/s
fentry : 4.201 ± 0.558M/s
fexit : 4.309 ± 0.148M/s
fmodret : 4.314 ± 0.203M/s
/* selftest: single-threaded, no atomics */
task_rename base 4555K events per sec
task_rename kprobe 3643K events per sec
task_rename kretprobe 2506K events per sec
task_rename raw_tp 4303K events per sec
task_rename fentry 4307K events per sec
task_rename fexit 4010K events per sec
task_rename fmod_ret 3984K events per sec
Multi-threaded implementations
==============================
/* bench: multi-threaded w/ atomics */
base : 3.910 ± 0.023M/s
kprobe : 3.048 ± 0.037M/s
kretprobe : 2.300 ± 0.015M/s
rawtp : 3.687 ± 0.034M/s
fentry : 3.740 ± 0.087M/s
fexit : 3.510 ± 0.009M/s
fmodret : 3.485 ± 0.050M/s
/* selftest: multi-threaded w/ atomics */
task_rename base 3872K events per sec
task_rename kprobe 3068K events per sec
task_rename kretprobe 2350K events per sec
task_rename raw_tp 3731K events per sec
task_rename fentry 3639K events per sec
task_rename fexit 3558K events per sec
task_rename fmod_ret 3511K events per sec
/* selftest: multi-threaded, no atomics */
task_rename base 3945K events per sec
task_rename kprobe 3298K events per sec
task_rename kretprobe 2451K events per sec
task_rename raw_tp 3718K events per sec
task_rename fentry 3782K events per sec
task_rename fexit 3543K events per sec
task_rename fmod_ret 3526K events per sec
Note that the fact that ./bench benchmark always uses atomic increments for
counting, while test_overhead doesn't, doesn't influence test results all that
much.
Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
---
tools/testing/selftests/bpf/Makefile | 4 +-
tools/testing/selftests/bpf/bench.c | 14 ++
.../selftests/bpf/benchs/bench_rename.c | 195 ++++++++++++++++++
.../selftests/bpf/benchs/run_bench_rename.sh | 9 +
.../selftests/bpf/prog_tests/test_overhead.c | 14 +-
.../selftests/bpf/progs/test_overhead.c | 6 +
6 files changed, 240 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/bpf/benchs/bench_rename.c
create mode 100755 tools/testing/selftests/bpf/benchs/run_bench_rename.sh
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 2ad0ef00f45c..3c43d4eceba8 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -410,10 +410,12 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h
$(call msg,CC,,$@)
$(CC) $(CFLAGS) -c $(filter %.c,$^) $(LDLIBS) -o $@
+$(OUTPUT)/bench_rename.o: $(OUTPUT)/test_overhead.skel.h
$(OUTPUT)/bench.o: bench.h testing_helpers.h
$(OUTPUT)/bench: LDLIBS += -lm
$(OUTPUT)/bench: $(OUTPUT)/bench.o $(OUTPUT)/testing_helpers.o \
- $(OUTPUT)/bench_count.o
+ $(OUTPUT)/bench_count.o \
+ $(OUTPUT)/bench_rename.o
$(call msg,BINARY,,$@)
$(CC) $(LDFLAGS) -o $@ $(filter %.a %.o,$^) $(LDLIBS)
diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index 3972da8b19e8..c9e8b7dbaf66 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -297,10 +297,24 @@ const struct bench *bench = NULL;
extern const struct bench bench_count_global;
extern const struct bench bench_count_local;
+extern const struct bench bench_rename_base;
+extern const struct bench bench_rename_kprobe;
+extern const struct bench bench_rename_kretprobe;
+extern const struct bench bench_rename_rawtp;
+extern const struct bench bench_rename_fentry;
+extern const struct bench bench_rename_fexit;
+extern const struct bench bench_rename_fmodret;
static const struct bench *benchs[] = {
&bench_count_global,
&bench_count_local,
+ &bench_rename_base,
+ &bench_rename_kprobe,
+ &bench_rename_kretprobe,
+ &bench_rename_rawtp,
+ &bench_rename_fentry,
+ &bench_rename_fexit,
+ &bench_rename_fmodret,
};
static void setup_benchmark()
diff --git a/tools/testing/selftests/bpf/benchs/bench_rename.c b/tools/testing/selftests/bpf/benchs/bench_rename.c
new file mode 100644
index 000000000000..e74cff40f4fe
--- /dev/null
+++ b/tools/testing/selftests/bpf/benchs/bench_rename.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <fcntl.h>
+#include "bench.h"
+#include "test_overhead.skel.h"
+
+/* BPF triggering benchmarks */
+static struct ctx {
+ struct test_overhead *skel;
+ struct counter hits;
+ int fd;
+} ctx;
+
+static void validate()
+{
+ if (env.producer_cnt != 1) {
+ fprintf(stderr, "benchmark doesn't support multi-producer!\n");
+ exit(1);
+ }
+ if (env.consumer_cnt != 1) {
+ fprintf(stderr, "benchmark doesn't support multi-consumer!\n");
+ exit(1);
+ }
+}
+
+static void *producer(void *input)
+{
+ char buf[] = "test_overhead";
+ int err;
+
+ while (true) {
+ err = write(ctx.fd, buf, sizeof(buf));
+ if (err < 0) {
+ fprintf(stderr, "write failed\n");
+ exit(1);
+ }
+ atomic_inc(&ctx.hits.value);
+ }
+}
+
+static void measure(struct bench_res *res)
+{
+ res->hits = atomic_swap(&ctx.hits.value, 0);
+}
+
+static void setup_ctx()
+{
+ setup_libbpf();
+
+ ctx.skel = test_overhead__open_and_load();
+ if (!ctx.skel) {
+ fprintf(stderr, "failed to open skeleton\n");
+ exit(1);
+ }
+
+ ctx.fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
+ if (ctx.fd < 0) {
+ fprintf(stderr, "failed to open /proc/self/comm: %d\n", -errno);
+ exit(1);
+ }
+}
+
+static void attach_bpf(struct bpf_program *prog)
+{
+ struct bpf_link *link;
+
+ link = bpf_program__attach(prog);
+ if (IS_ERR(link)) {
+ fprintf(stderr, "failed to attach program!\n");
+ exit(1);
+ }
+}
+
+static void setup_base()
+{
+ setup_ctx();
+}
+
+static void setup_kprobe()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog1);
+}
+
+static void setup_kretprobe()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog2);
+}
+
+static void setup_rawtp()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog3);
+}
+
+static void setup_fentry()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog4);
+}
+
+static void setup_fexit()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog5);
+}
+
+static void setup_fmodret()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog6);
+}
+
+static void *consumer(void *input)
+{
+ return NULL;
+}
+
+const struct bench bench_rename_base = {
+ .name = "rename-base",
+ .validate = validate,
+ .setup = setup_base,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_kprobe = {
+ .name = "rename-kprobe",
+ .validate = validate,
+ .setup = setup_kprobe,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_kretprobe = {
+ .name = "rename-kretprobe",
+ .validate = validate,
+ .setup = setup_kretprobe,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_rawtp = {
+ .name = "rename-rawtp",
+ .validate = validate,
+ .setup = setup_rawtp,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fentry = {
+ .name = "rename-fentry",
+ .validate = validate,
+ .setup = setup_fentry,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fexit = {
+ .name = "rename-fexit",
+ .validate = validate,
+ .setup = setup_fexit,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fmodret = {
+ .name = "rename-fmodret",
+ .validate = validate,
+ .setup = setup_fmodret,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
diff --git a/tools/testing/selftests/bpf/benchs/run_bench_rename.sh b/tools/testing/selftests/bpf/benchs/run_bench_rename.sh
new file mode 100755
index 000000000000..16f774b1cdbe
--- /dev/null
+++ b/tools/testing/selftests/bpf/benchs/run_bench_rename.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+set -eufo pipefail
+
+for i in base kprobe kretprobe rawtp fentry fexit fmodret
+do
+ summary=$(sudo ./bench -w2 -d5 -a rename-$i | tail -n1 | cut -d'(' -f1 | cut -d' ' -f3-)
+ printf "%-10s: %s\n" $i "$summary"
+done
diff --git a/tools/testing/selftests/bpf/prog_tests/test_overhead.c b/tools/testing/selftests/bpf/prog_tests/test_overhead.c
index 465b371a561d..2702df2b2343 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_overhead.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_overhead.c
@@ -61,9 +61,10 @@ void test_test_overhead(void)
const char *raw_tp_name = "raw_tp/task_rename";
const char *fentry_name = "fentry/__set_task_comm";
const char *fexit_name = "fexit/__set_task_comm";
+ const char *fmodret_name = "fmod_ret/__set_task_comm";
const char *kprobe_func = "__set_task_comm";
struct bpf_program *kprobe_prog, *kretprobe_prog, *raw_tp_prog;
- struct bpf_program *fentry_prog, *fexit_prog;
+ struct bpf_program *fentry_prog, *fexit_prog, *fmodret_prog;
struct bpf_object *obj;
struct bpf_link *link;
int err, duration = 0;
@@ -96,6 +97,10 @@ void test_test_overhead(void)
if (CHECK(!fexit_prog, "find_probe",
"prog '%s' not found\n", fexit_name))
goto cleanup;
+ fmodret_prog = bpf_object__find_program_by_title(obj, fmodret_name);
+ if (CHECK(!fmodret_prog, "find_probe",
+ "prog '%s' not found\n", fmodret_name))
+ goto cleanup;
err = bpf_object__load(obj);
if (CHECK(err, "obj_load", "err %d\n", err))
@@ -142,6 +147,13 @@ void test_test_overhead(void)
goto cleanup;
test_run("fexit");
bpf_link__destroy(link);
+
+ /* attach fmod_ret */
+ link = bpf_program__attach_trace(fmodret_prog);
+ if (CHECK(IS_ERR(link), "attach fmod_ret", "err %ld\n", PTR_ERR(link)))
+ goto cleanup;
+ test_run("fmod_ret");
+ bpf_link__destroy(link);
cleanup:
prctl(PR_SET_NAME, comm, 0L, 0L, 0L);
bpf_object__close(obj);
diff --git a/tools/testing/selftests/bpf/progs/test_overhead.c b/tools/testing/selftests/bpf/progs/test_overhead.c
index 56a50b25cd33..450bf819beac 100644
--- a/tools/testing/selftests/bpf/progs/test_overhead.c
+++ b/tools/testing/selftests/bpf/progs/test_overhead.c
@@ -39,4 +39,10 @@ int BPF_PROG(prog5, struct task_struct *tsk, const char *buf, bool exec)
return !tsk;
}
+SEC("fmod_ret/__set_task_comm")
+int BPF_PROG(prog6, struct task_struct *tsk, const char *buf, bool exec)
+{
+ return !tsk;
+}
+
char _license[] SEC("license") = "GPL";
--
2.24.1
